A blood amulet of fury is a neck slot item made by combining an amulet of fury with a blood necklace shard. This process requires 80 Crafting, which can be assisted, and awards 200 experience. However, the process cannot be reversed, and the amulet permanently becomes untradeable. When created, it is fully charged.

While in combat, the amulet has a passive effect that damages monsters for 200 to 500 life points and heals the wearer for the same amount every 15 seconds. The amulet will target the monster that last damaged the wearer or the monster the wearer last damaged (whichever was most recent), and any other nearby monsters (even if they aren't in combat with the wearer). The maximum the amulet can heal per activation is 1,200 life points. If the amulet was intended to do more damage than its target had left (e.g. the target had 240 life points, and the amulet rolled to hit a 500), then the amulet will still heal the full amount to its wearer.

If the blood amulet of fury is lost on death in a PvP situation, 50,000 coins are dropped.

The passive effect does not work against most boss monsters, specifically ones that are immune to reflect damage (i.e. Deflect curses, etc). The exceptions to this (i.e. the passive effect will work) are:

The amulet degrades in combat, and lasts for 60,000 charges before it becomes empty. Even after the amulet runs out of charge, it retains its combat bonuses and may be equipped and used, but without the healing effect. A full recharge costs:

1,000,000 coins with a 0.5% discount per Smithing level of the repairer at an armour stand

The Smithing level at which the cost is equal is -30; thus, using blood runes is never cheaper.

Unlike most other items repairable on an armour stand, the repair of blood necklaces is rounded up to the nearest 1% of the charge (e.g. repairing an amulet with 52.5% charge remaining will charge for a 48% repair).

When using 2000 blood runes to recharge the amulet, players can first choose to charge it with 1 blood rune to get 0.1% charge leaving 1999 blood runes left. Using the remaining runes on the amulet will let players choose 1980 runes to be use on the amulet instead of 1999. Choosing 1980 will charge the amulet to 100%, leaving behind 19 blood runes extra. It is currently unknown whether this is a bug.